Oil testing apparatus



Oct. 24, 1939.

B. E. SIBLEY OIL TESTING APPARATUS Filed Feb. 15, 1937 2 Sheets-Sheet lATTOR EY B. E. slBLx-:Y 2,177,293

Oct 24, 1939.

OIL TESTING APPARATUS Filed Feb. 13, 1957 2 Sheets-Sheet 2 INVENTOR l w/i/ f 5dr/'effi .S/'ZQ/ey g l I BY e ATTORN Y Patented Oct. 24, 1939UNITED STATES PATENT VOFFICE om TEs'rrNG APPARATUS Application February13, 1937, LSerial No. 125,620 i Claim. (Cl. 265-10) My invention relatesto oil testing apparatus and more particularly toa machine or apparatusfor testing lubricating qualities and more especially the comparativeload carrying ability of two lubricating oils.

Ascertaining the lubricating properties of lubricating oils isl adiilcult matter since results will vary not only inv accordance withnthelubricating properties of the oils being tested but n l0 also with thenature of the metallic surfaces moving on one another separated by theoil film, the temperature at which the test is conducted, the loadapplied, the speed of relative movement `of the two surfaces, the rateat which the load is applied, they rate of oil fed to the test shaft,and the pressure at which the oil is applied. If a test is conducted onone oil and the conditions noted, and it is attempted to duplicate theseconditions with another oil, due to the many variable factors, it ispossible for error to creep in.

One object of my invention is to provide a testing machine for comparingtwo lubricants in which the respective oils being tested are subjectedto precisely the same conditions of testing with respect to the rate ofloading, the rate of oil fed to the test shaft, the rate of speed of thetest shaft, uthe temperature, the degree `of loading and anyotherfactors or conditions which might develop during testing.

4 Another object of my invention is toprovide a machine for testing thefilm strength of the oil nlm-established by an oil between moving partsto be lubricated.

Another object f my invention is to provide an apparatus forascertaining in a simple and convenient manner, the lm strength of alubricating oil.

Another object of my invention is to provide a handy assembly fortesting the fijm strength of lubricants, which assembly is easy ofoperation, light enough in weight to be portable and strong enough instructure to be durable. l

Other and further objects of my invention will 45 appear from thefollowing description.

Ingeneral, my invention contemplates the provision of a pair of testbearings in which test shafts are adapted torotate, driven from a commonsource and in which identical conditions of D quantity of loading, rateof loading, speed of rotation and oil supply are provided so thatcomparative results may beobtained.

In ythe accompanying drawings which form part of the instantspecification and which are to y., be read in conjunction therewith, andin which like reference numerals are used to indicate like parts in thevarious views;

Figure 1 is a plan view of my testing assembly.

Figure 2 is a side elevation of the testing assembly shownrr in Figurel.

Figure 31s a sectional view taken on a line 3-3 of Figure 1.

, Figure 4 is a sectional view taken on a line 4--4 of Figure 1. l

Figure 5 is a sectional view taken on a line 5-5 of Figure 2.

Figure 6 is an enlarged fragmentary sectional view taken on a line 6-6of Figure 1.

Figure '7 is an isometric view of a portion of the test apparatusshowing the mode of assembly.

More particularly referring now to the drawings, to a suitable bed plateI I secure a motor spacer and belt tightener 2 which spaces an electricmotor 3 which, through a suitable transmission housed in housing 4, isadapted to drive a 1 shaft 5 to which is keyed a driving sheave 6. 'I'hemotor is of a constant speed type and may be, for example, a one-thirdhorsepower motor,

designed for 310 R. P. M. The gear housed in housing 4 may be aplanetary gear and a .ratio g of 5.57 to l has been found satisfactoryin use. By-rotating the head 1 of stud bolt 8, the motor assembly may bemoved outwardly or inwardly to tighten the belt 9 which drives the oilpump and testing shafts as hereinafter will be more fully pointedout.Upon the bed plate I, I mount a pump casing I0 in which a reciprocatingpump assembly II is mounted.V An oil reservoir I2, adapted to supply oilto the pump Il, is also mounted within the casing I0.- 'Ihe pumpassembly II is provided with a pump cylinder I3 in which a pump plungerI4 is adapted to be reciprocated to pump oil taken from reservoir l2past check valve I5, through oil line I6, into oil manifold I1. A sheaveI8 is keyedv to vshaft I3, to 40 which is keyed withincasing I Il a worm20. 'The worm is adapted to rotate worm wheel 2l which is secured toshaft 22. A pump bushing 23 houses crank pin 24 which is adaptedto'reciprocate plunger shoe 25 for reciprocating the pump 45 plunger I4.The belt 9 also drives main drive sheave 28 which drives drive shafts 26and 21 through shear pins 29' and 33 respectively.

Mounted on bed plate I are suitable supports 3I and 32, carrying bearinghousings 33 and 34 50 respectively. Bearing housing 33 houses ballbearings 35 and bearing housing 34 housesball bearings 36. A pilot shaft3l is provided witha bushing 38 for rotation on ball bearings 35. Driveshaft 27 extends into ball bearings 36. The test bearing 39 is made inthe form of a hexagon through which is drilled a carefully reamed, axialopening 40 in which a test shaft 4I is adapted to rotate with a knownpre-determined clearance.

It will be observed that test bearing 39 and test shaft 4I vmust beaccurately made in order to obtain reproducible and uniformly accurateresults. Likewise, they must be made out of the same materials. Ifdesired, the test bearings may be made out of different material and thesame oil employed in order to obtain comparative results on two bearingmetals with a single test. An oil hole 42 is provided at the top of thetest bearing 39 as can readily be seen by reference to Figure 7. Thetest bearing is adapted to beheld by a test bearing holder 43. 'I'heholder 43 is provided with a lug 44 adapted to rest upon a holdersupport rod 45, mounted in bed plate I. The ltest'holder lug 44 and thesupport rod' 45 prevent the test holder bearing from rotating during atest upon rotation of the test shaft. The test shaft 4| is provided withflattened ends 46 and 41 adapted to fit in correspondingly shapedsockets in the pilot shaft 31 and drive shaft 21 respectively. 'Ihepilot shaft 31 is provided with a pin 46 which is adapted to lock in abayonet slot 49, formed in the head of bushing 38. The flattened end 46flts within pilot shaft 31 with sufficient friction to enable theremoval of lthe pilot shaft to carry with it the test shaft 4I and thisenables the assembly and removal of a series of test shafts and testbearings for respective tests in a simple and convenient manner. Thetest holder 43 is drilled with an oil duct 50 which is aligned with oilduct `42 1n the test bearing. An oil feeder funnel 5I communicates withoil duct 50. A,test oil reservoir 52 which is in the form of acalibrated glass tube, is adapted to contain the sample of the oil to betested. A` valve 53 is provided for removing oil from the test oilreservoir 52 for transfer to the test oil feeder funnel 5I.

The load is applied to the test bearings through a hydraulic systemconnected with manifold I1 whereby the output of the pump assembly II istransferred through conduit 54 to the interior of loading cylinder 55 inwhich a loading piston 56 is assembled. The loading piston 56 carries aloading plunger 51 which is adapted to apply a load upon test bearingholder 43 through ball bearing 58 which abuts test bearing holder shoe59. Also connected to manifold I1 is a conduit 60 which is adapted todischarge into spring loading cylinder head 6I of rspring holdingcylinder 62 in which there is housed a spring loading piston 63 and aloading spring 64.' The loading spring is a fairly heavy spring and maybe of" about 2" outside diameter, made of diameter v steel havinga'i31/2" free length in seven coils."

After the thrust against the test bearing reaches a predetermined point,a portion of the oil being pumped by the pumping assembly I will4 forcethe spring loading piston downwardlyagainst the action of the loadingspring. The compression of the spring exerts a pressure upon thehydraulic system which is transferred to the loading piston and loadingplunger 51. Conduit '66 communicates with manifold I1 and is adapted toconvey oil under the pressure of the hydraulic system to the mastergauge support 61 on which is supported master gauge 65. The pressure ofthe' hydraulic system is transmitted to the gauge 65 through conduit 66which is in communication with the pressure system as can readily beseen by reference to Figure 6. It will be obvious that ythe pressureimposed upo'n the test bearing will be indicated by the master gauge.The gauge may be calibrated directly in pounds per square inch. In orderto release the load upon the test fibearing, I provide a release valve69 which, upon being opened, releases the oil `under pressure throughduct 10 to the reservoir I2. The release valve is provided with apacking nut 1I to prevent the escape of oil under pressure.

When it is desired to make a test, fresh test bearings and test shaftsare assembled in the position shown in Figure 5, it being understood ofcourse that shear pins 29 and 30 are in place. lThese shear pins may bemade of any suitable material, as for example 12`gauge brass metallizingwire. Samples of lubricating oils to be tested arethen placed in thetest sample reservoirs 52 and valves 53 are opened to permit a portionof the sample to run into the feed funnels 5I. When the feed funnels arei'llled to a predetermined point, the valves 53 are closed and theapparatus is ready to begin the test. The motor 3 is then started andits operation will drive pump pulleys I8 and 26 pumping oil through thehydraulic system and applying pressure upon the vtest bearings throughtest bearing holders' 43 and also applying pressure upon the loadingspring in loading spring cylinder 62, thus insuring a uniform pressurethroughout thev hydraulic system, irrespective of strokes of thereciprocating hydraulic system pump plunger. The pressure applied inpounds per square inch is read directly from the master gauge 65. Itwill be observed that, as long as shear pins 30 and 29 are intact, testdrive shafts 26 and 21 will be rotated, thus driving test shafts 4Iwhich, in turn will drive pilot shafts 31. The ends of pilot shafts 31terminate in knurled knobs 15 which can be observed by the operator. Assoon as the motor is started, the oil in the feed funnel will dropslightly in level due to a portion of it being used to establish an oillm between the test shaft and the test bearing. The valves 58 are openedslightly to permit a constant slow feed of oil during the test. Theamount of valve opening can be readil? determined in practice byobserving the level n the feed funnels. When the load becomes so greatthat the oil film between a test bearing and the test shaft is ruptured,the two test piece's willseize and friction will prevent the test shaftfrom turning in thetest bearing. The test bearing 'cannot turn becauseit is held by the test bearing holder 43 as will be obvious from thedescription hereinbefore. Upon seizure the shear pin of the particulartest drive shaft driving the seized shaft will shear. At dthis point,the pressure upon the gauge can be read and since it is calibrated inpounds per square inch, the load carryingvability of the` particularsample load noted. The shearing of the shear pin on the side whereseizure occurred will permit the main driving sheave to operate withoutany reduction in speed. The other side will continue to operate asdescribed and pressure will continue to build up until either seizure-has occurred or a predetermined load is reached, at which time themachine may be stopped. Y

It will be observed that I have accomplished the objects of myinvention. I have provided a testing machine for testing lubricatingqualities of hydrocarbon cils and more particularly their load carryingabilities wherein two oils are tested simultaneously under identicalconditions of test so that an accurate comparison may be obtained.

It will be understood that certain features and sub-combinations are ofutility and may be employed without reference to other Afeatures andsub-combinations. vThis is contemplated by and is within the scope of myclaim. It is further obvious that various changes may be made in details within the scope of my claim without departing from the spirit ofmy invention. It is, therefore, to be understood that my invention isnot to be limited to the specic details shown and g described. y v

- l Having thus descrbedvmy invention, what I claim is:

In an oil-testing apparatus, a prime mover, a hydraulic pump and adriving shaft driven by said prime mover, a pair of test bearingholders, test bearings mounted within said respective holders, testshafts mounted for rotation within said respective test bearings, meansincluding shear means for coupling said driving shaft to said testshafts, means for applying the hydraulic pressure developed by saidhydraulic pump to said test bearing holders for transmission to saidtest bearings, and means for measuring the hydraulic pressure generated.

BARRE'I'I E. SIBLEY.

